agora inbox for [email protected]  
help / color / mirror / Atom feed
From: Peter Eisentraut <[email protected]>
Subject: [PATCH v2 1/2] Better error messages for short reads/writes in SLRU
Date: Mon, 26 Aug 2019 21:37:10 +0200

This avoids getting a

    Could not read from file ...: Success.

for a short read or write (since errno is not set in that case).
Instead, report a more specific error messages.
---
 src/backend/access/transam/slru.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
index 0fbcb4e6fe..e38f9199dd 100644
--- a/src/backend/access/transam/slru.c
+++ b/src/backend/access/transam/slru.c
@@ -920,18 +920,29 @@ SlruReportIOError(SlruCtl ctl, int pageno, TransactionId xid)
 							   path, offset)));
 			break;
 		case SLRU_READ_FAILED:
-			ereport(ERROR,
-					(errcode_for_file_access(),
-					 errmsg("could not access status of transaction %u", xid),
-					 errdetail("Could not read from file \"%s\" at offset %u: %m.",
-							   path, offset)));
+			if (errno)
+				ereport(ERROR,
+						(errcode_for_file_access(),
+						 errmsg("could not access status of transaction %u", xid),
+						 errdetail("Could not read from file \"%s\" at offset %u: %m.",
+								   path, offset)));
+			else
+				ereport(ERROR,
+						(errmsg("could not access status of transaction %u", xid),
+						 errdetail("Could not read from file \"%s\" at offset %u: read too few bytes.", path, offset)));
 			break;
 		case SLRU_WRITE_FAILED:
-			ereport(ERROR,
-					(errcode_for_file_access(),
-					 errmsg("could not access status of transaction %u", xid),
-					 errdetail("Could not write to file \"%s\" at offset %u: %m.",
-							   path, offset)));
+			if (errno)
+				ereport(ERROR,
+						(errcode_for_file_access(),
+						 errmsg("could not access status of transaction %u", xid),
+						 errdetail("Could not write to file \"%s\" at offset %u: %m.",
+								   path, offset)));
+			else
+				ereport(ERROR,
+						(errmsg("could not access status of transaction %u", xid),
+						 errdetail("Could not write to file \"%s\" at offset %u: wrote too few bytes.",
+								   path, offset)));
 			break;
 		case SLRU_FSYNC_FAILED:
 			ereport(data_sync_elevel(ERROR),

base-commit: acb96eb7d294a003a9392cdd445630ef137d9918
-- 
2.22.0


--------------893F683A237131F02D66269A
Content-Type: text/plain; charset=UTF-8; x-mac-type="0"; x-mac-creator="0";
 name="v2-0002-pg_checksums-Handle-read-and-write-returns-correc.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename*0="v2-0002-pg_checksums-Handle-read-and-write-returns-correc.pa";
 filename*1="tch"



view thread (2+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected]
  Subject: Re: [PATCH v2 1/2] Better error messages for short reads/writes in SLRU
  In-Reply-To: <no-message-id-1882140@localhost>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox